/* Keep a continuous fine rail behind the stronger current-section segment.
   Article sidebars already reserve this space; other vertical indexes need it. */
html body main [data-section-index][data-section-orientation="rail"]:not(.article-nav) a[href^="#"] {
  border-left: 1px solid var(--line);
  padding-left: 14px;
}
/* Current reading position uses the existing accent without moving link text.
   Native hover/focus, link targets and responsive index layouts remain intact. */
html body main [data-section-index] a[aria-current="location"] {
  color: var(--accent);
  box-shadow: inset 0 -3px 0 currentColor;
}
html body main [data-section-index][data-section-orientation="rail"] a[aria-current="location"] {
  box-shadow: inset 3px 0 0 currentColor;
  border-left-color: currentColor;
}
@media (forced-colors: active) {
  html body main [data-section-index] a[aria-current="location"] {
    color: LinkText;
    text-decoration-line: underline;
    text-decoration-thickness: .2em;
    box-shadow: none;
    outline: 2px solid Highlight;
    outline-offset: -2px;
  }
}
@media print {
  html body main [data-section-index] a[aria-current="location"] {
    box-shadow: none;
    text-decoration-thickness: auto;
  }
}